RV A/C ceiling vent changes -- could use some tips

You got me looking at mine since I would like to get vents that close so I can force more air to the vents I want. When I pulled off the vent cover I noticed that the extension that attaches to the duck work was taped but very poorly, I used some aluminum tape and fixed all the vents and maybe it is just in my head, but it seams that they all blow better still. I still need to find vents that fit my trailer but this has helped I think, just thought you may want to check yours too.

Leon